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GCN Circulars

GCN Circulars are rapid bulletins submitted by and distributed to the community. See the documentation for help with subscribing to or submitting Circulars.

Search for Circulars by submitter, subject, or body text (e.g. 'Fermi GRB').
To navigate to a specific circular, enter the associated Circular ID (e.g. 'gcn123', 'Circular 123', or '123').
Advanced Search

To narrow the search results, use advanced search syntax. This allows for specifying which circular field to search (submitter, subject, and/or body). For additional information, refer to the advanced search documentation.

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subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

26542 results found.

  1. EP260105a: LCO Optical Upper limit
  2. EP260104a: Einstein Probe detection of a fast X-ray transient
  3. GRB 260101A: COLIBRÍ optical upper limits
  4. EP260105a: Einstein Probe detection of an X-ray transient
  5. GRB 260104A: COLIBRÍ optical upper limits
  6. GRB 251230A/EP-WXT trigger 01709250693: Mephisto optical upper limits
  7. GRB 260104A: Swift-XRT refined Analysis
  8. GRB 260104A: Enhanced Swift-XRT position
  9. GRB 260101A: Swift/UVOT Detection
  10. GRB 260104A: Swift detection of a burst
  11. Fermi-LAT Gamma-ray Observations of IceCube-251225A
  12. GRB 260101A: COLIBRÍ optical observations
  13. GRB 260102B: Fermi GBM Final Real-time Localization
  14. GRB 260102A: LCO optical upper limits
  15. GRB 260102A: Swift-XRT observations
  16. GRB 260102A: SVOM/COLIBRÍ (FM-GFT) optical observations
  17. GRB 260102A: SVOM/VT optical counterpart
  18. GRB 260101A: Fermi GBM Observation
  19. EP260101a: refined analysis of the EP-WXT and EP-FXT observations
  20. GRB 260102A: SVOM detection of a burst
  21. GRB 260101A: SVOM/GRM observation
  22. GRB 260101A: Swift-XRT refined Analysis
  23. GRB 260101A: Enhanced Swift-XRT position
  24. EP260101a: Einstein Probe detection of an X-ray transient
  25. GRB 260101A: OSIRIS+ redshift z = 2.623 for the new year burst
  26. GRB 260101A: LCO detection of the optical counterpart
  27. GRB 260101A: Swift detection of a burst with an optical counterpart
  28. GRB 251230A: GRANDMA/TAROT Early Detection
  29. GRB 251230A/EP251230a: Optical upper limit with Kinder observations
  30. EP251229a: Optical upper limit with Kinder observations
  31. GRB 251230A: 1.3m DFOT optical upper limit
  32. GRB 251230A: Swift-XRT refined Analysis
  33. GRB 251222A: Mondy Optical Observations
  34. EP251230a / GRB 251230A: refined analysis of the EP-WXT and EP-FXT observations
  35. GRB 251230A: Swift/UVOT detection
  36. GRB251230A: 7DT optical upper limits
  37. EP251229a: BOOTES-2 early optical upper limit
  38. GRB 251230A: GOTO optical upper limit
  39. EP251229a: NOT optical upper limits
  40. GRB 251230A / EP251230a: SVOM/VT optical observation
  41. EP251229a: refined analysis of the EP-WXT and EP-FXT observations
  42. GRB 251230A: Enhanced Swift-XRT position
  43. GRB 251230A: Early optical counterpart detection by LCO.
  44. EP-WXT trigger 01709250662 Mephisto and 50cm telescope follow-up
  45. EP251230a / GRB 251230A: Einstein Probe detection of an X-ray transient
  46. GRB 251230A/EP#01709250693 (likely EP251230a): FTW optical and NIR observations
  47. LIGO/Virgo/KAGRA S251112cm: Candidates from the NSF-DOE Vera C. Rubin Observatory
  48. EP251229a: Einstein Probe detection of an X-ray transient
  49. GRB 251230A: Swift detection of a burst with a bright optical counterpart
  50. GRB 251226A: Glowbug gamma-ray detection
  51. GRB 251222A/EP251222b: 1.6m Mephisto optical followup
  52. The EP-WXT trigger 01709250662 is likely a flaring star
  53. GRB 251226A: SVOM/GRM observation
  54. IceCube-251225A: Upper limits from a search for additional neutrino events in IceCube
  55. The EP-WXT trigger 01709250617 is likely a flaring star
  56. IceCube Alert 251225.84: Global MASTER-Net observations report
  57. GRB 251222A/EP251222b: Optical detection with Kinder observations
  58. EP251222a: Optical upper limit with Kinder observations
  59. GRB 251205A: Kilonova-Catcher optical afterglow detection
  60. GRB 251222A: AbAO optical observations
  61. GRB 251222A / EP251222b: Kilonova-Catcher optical afterglow detection
  62. GRB 251222A: ZTSH BVRI optical observations
  63. GRB 251222A: SVOM/COLIBRÍ (FM-GFT) optical observations
  64. GRB 251222A: Continued 1.3m DFOT optical observation
  65. EP251220a: 3.6m DOT optical afterglow detection
  66. GRB 251222A: Fermi GBM Observation
  67. EP251220a: CrAO ZTSh optical observations
  68. EP251221a: PRIME upper limit
  69. EP251221a: Liverpool Telescope upper limits
  70. EP251222a: refined analysis of the EP-WXT and EP-FXT observations
  71. EP251222b/GRB 251222A: refined analysis of the EP-WXT and EP-FXT observations
  72. Konus-Wind detection of GRB 251222A / EP251222b
  73. GRB 251222A: Swift-XRT afterglow detection
  74. GRB 251222A / EP251222b: LCO detection of the optical counterpart
  75. EP251222a: NTT/ULTRACAM optical observations
  76. GRB 251222A / EP251222b: GOTO optical counterpart detection
  77. GRB 251222A / EP251222b: LCO optical observations
  78. GRB 251222A: 1.3m DFOT optical detection
  79. GRB251221A: 7DT optical upper limits
  80. EP251222a: GSP Optical Counterpart Detection
  81. GRB 251222A / EP251222b: VLT/X-shooter spectroscopic redshift z = 3.171
  82. EP251222b/GRB 251222A: SVOM/GRM observation
  83. EP251222b/GRB 251222A: Einstein Probe detection of an X-ray transient
  84. EP251222a: Einstein Probe detection of an X-ray transient
  85. The EP-WXT trigger 01709250397 is likely a flaring star
  86. GRB 251222A: PRIME near-infrared detection
  87. EP251221a: NOT optical upper limit
  88. GRB 251222A: Calapai Observatory, Massa S. Giorgio (Messina), optical observation.
  89. IceCube-251218A: No Candidate Transients from the Zwicky Transient Facility
  90. IPN triangulation of GRB 251220B (short)
  91. GRB 251222A: SVOM/VT optical candidate
  92. GRB 251222A: SVOM detection of a long burst
  93. EP251220a: PRIME upper limit
  94. GRB 251221A: PRIME near-infrared observation
  95. GRB 251221A: UAFO and Mondy optical upper limit
  96. GRB 251221A: Swift-XRT refined Analysis
  97. EP251221a: Einstein Probe detection of a fast X-ray transient
  98. GRB 251221A: Swift/UVOT Upper Limits
  99. GRB 251221A: Enhanced Swift-XRT position
  100. GRB 251221A: Fermi GBM Observation

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